package cn.xabad.commons.tools;

import cn.xabad.commons.lang3.StringUtils;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;


public class StemmerU {
    private char[] b;
    private int i,     /* offset into b */
            i_end, /* offset to end of stemmed word */
            j, k;
    private static final int INC = 50;

    /* unit of size whereby b is increased */
    public StemmerU() {
        b = new char[INC];
        i = 0;
        i_end = 0;
    }

    public void add(char ch) {
        if (i == b.length) {
            char[] new_b = new char[i + INC];
            for (int c = 0; c < i; c++) new_b[c] = b[c];
            b = new_b;
        }
        b[i++] = ch;
    }

    public void add(char[] w, int wLen) {
        if (i + wLen >= b.length) {
            char[] new_b = new char[i + wLen + INC];
            for (int c = 0; c < i; c++) new_b[c] = b[c];
            b = new_b;
        }
        for (int c = 0; c < wLen; c++) b[i++] = w[c];
    }

    public String toString() {
        return new String(b, 0, i_end);
    }

    public int getResultLength() {
        return i_end;
    }

    public char[] getResultBuffer() {
        return b;
    }


    private final boolean cons(int i) {
        switch (b[i]) {
            case 'a':
            case 'e':
            case 'i':
            case 'o':
            case 'u':
                return false;
            case 'y':
                return (i == 0) ? true : !cons(i - 1);
            default:
                return true;
        }
    }


    private final int m() {
        int n = 0;
        int i = 0;
        while (true) {
            if (i > j) return n;
            if (!cons(i)) break;
            i++;
        }
        i++;
        while (true) {
            while (true) {
                if (i > j) return n;
                if (cons(i)) break;
                i++;
            }
            i++;
            n++;
            while (true) {
                if (i > j) return n;
                if (!cons(i)) break;
                i++;
            }
            i++;
        }
    }

    private final boolean vowelinstem() {
        int i;
        for (i = 0; i <= j; i++) if (!cons(i)) return true;
        return false;
    }

    private final boolean doublec(int j) {
        if (j < 1) return false;
        if (b[j] != b[j - 1]) return false;
        return cons(j);
    }

    private final boolean cvc(int i) {
        if (i < 2 || !cons(i) || cons(i - 1) || !cons(i - 2)) return false;
        {
            int ch = b[i];
            if (ch == 'w' || ch == 'x' || ch == 'y') return false;
        }
        return true;
    }

    private final boolean ends(String s) {
        int l = s.length();
        int o = k - l + 1;
        if (o < 0) return false;
        for (int i = 0; i < l; i++) if (b[o + i] != s.charAt(i)) return false;
        j = k - l;
        return true;
    }

    private final void setto(String s) {
        int l = s.length();
        int o = j + 1;
        for (int i = 0; i < l; i++) b[o + i] = s.charAt(i);
        k = j + l;
    }

    private final void r(String s) {
        if (m() > 0) setto(s);
    }


    private final void step1() {
        if (b[k] == 's') {
            if (ends("sses")) k -= 2;
            else if (ends("ies")) setto("i");
            else if (b[k - 1] != 's') k--;
        }
        if (ends("eed")) {
            if (m() > 0) k--;
        } else if ((ends("ed") || ends("ing")) && vowelinstem()) {
            k = j;
            if (ends("at")) setto("ate");
            else if (ends("bl")) setto("ble");
            else if (ends("iz")) setto("ize");
            else if (doublec(k)) {
                k--;
                {
                    int ch = b[k];
                    if (ch == 'l' || ch == 's' || ch == 'z') k++;
                }
            } else if (m() == 1 && cvc(k)) setto("e");
        }
    }

   /* step2() turns terminal y to i when there is another vowel in the stem. */

    private final void step2() {
        if (ends("y") && vowelinstem()) b[k] = 'i';
    }

   /* step3() maps double suffices to single ones. so -ization ( = -ize plus
      -ation) maps to -ize etc. note that the string before the suffix must give
      m() > 0. */

    private final void step3() {
        if (k == 0) return; /* For Bug 1 */
        switch (b[k - 1]) {
            case 'a':
                if (ends("ational")) {
                    r("ate");
                    break;
                }
                if (ends("tional")) {
                    r("tion");
                    break;
                }
                break;
            case 'c':
                if (ends("enci")) {
                    r("ence");
                    break;
                }
                if (ends("anci")) {
                    r("ance");
                    break;
                }
                break;
            case 'e':
                if (ends("izer")) {
                    r("ize");
                    break;
                }
                break;
            case 'l':
                if (ends("bli")) {
                    r("ble");
                    break;
                }
                if (ends("alli")) {
                    r("al");
                    break;
                }
                if (ends("entli")) {
                    r("ent");
                    break;
                }
                if (ends("eli")) {
                    r("e");
                    break;
                }
                if (ends("ousli")) {
                    r("ous");
                    break;
                }
                break;
            case 'o':
                if (ends("ization")) {
                    r("ize");
                    break;
                }
                if (ends("ation")) {
                    r("ate");
                    break;
                }
                if (ends("ator")) {
                    r("ate");
                    break;
                }
                break;
            case 's':
                if (ends("alism")) {
                    r("al");
                    break;
                }
                if (ends("iveness")) {
                    r("ive");
                    break;
                }
                if (ends("fulness")) {
                    r("ful");
                    break;
                }
                if (ends("ousness")) {
                    r("ous");
                    break;
                }
                break;
            case 't':
                if (ends("aliti")) {
                    r("al");
                    break;
                }
                if (ends("iviti")) {
                    r("ive");
                    break;
                }
                if (ends("biliti")) {
                    r("ble");
                    break;
                }
                break;
            case 'g':
                if (ends("logi")) {
                    r("log");
                    break;
                }
        }
    }

   /* step4() deals with -ic-, -full, -ness etc. similar strategy to step3. */

    private final void step4() {
        switch (b[k]) {
            case 'e':
                if (ends("icate")) {
                    r("ic");
                    break;
                }
                if (ends("ative")) {
                    r("");
                    break;
                }
                if (ends("alize")) {
                    r("al");
                    break;
                }
                break;
            case 'i':
                if (ends("iciti")) {
                    r("ic");
                    break;
                }
                break;
            case 'l':
                if (ends("ical")) {
                    r("ic");
                    break;
                }
                if (ends("ful")) {
                    r("");
                    break;
                }
                break;
            case 's':
                if (ends("ness")) {
                    r("");
                    break;
                }
                break;
        }
    }

   /* step5() takes off -ant, -ence etc., in context <c>vcvc<v>. */

    private final void step5() {
        if (k == 0) return; /* for Bug 1 */
        switch (b[k - 1]) {
            case 'a':
                if (ends("al")) break;
                return;
            case 'c':
                if (ends("ance")) break;
                if (ends("ence")) break;
                return;
            case 'e':
                if (ends("er")) break;
                return;
            case 'i':
                if (ends("ic")) break;
                return;
            case 'l':
                if (ends("able")) break;
                if (ends("ible")) break;
                return;
            case 'n':
                if (ends("ant")) break;
                if (ends("ement")) break;
                if (ends("ment")) break;
                    /* element etc. not stripped before the m */
                if (ends("ent")) break;
                return;
            case 'o':
                if (ends("ion") && j >= 0 && (b[j] == 's' || b[j] == 't')) break;
                                    /* j >= 0 fixes Bug 2 */
                if (ends("ou")) break;
                return;
                    /* takes care of -ous */
            case 's':
                if (ends("ism")) break;
                return;
            case 't':
                if (ends("ate")) break;
                if (ends("iti")) break;
                return;
            case 'u':
                if (ends("ous")) break;
                return;
            case 'v':
                if (ends("ive")) break;
                return;
            case 'z':
                if (ends("ize")) break;
                return;
            default:
                return;
        }
        if (m() > 1) k = j;
    }

    private final void step6() {
        j = k;
        if (b[k] == 'e') {
            int a = m();
            if (a > 1 || a == 1 && !cvc(k - 1)) k--;
        }
        if (b[k] == 'l' && doublec(k) && m() > 1) k--;
    }

    public void stem() {
        k = i - 1;
        if (k > 1) {
            step1();
            step2();
            step3();
            step4();
            step5();
            step6();
        }
        i_end = k + 1;
        i = 0;
    }

    private static StemmerU stemmer;

    public static StemmerU getStemmer() {
        if (stemmer == null) {
            stemmer = new StemmerU();
        }
        return stemmer;
    }

    public static List<String> stemWord(String word) {
        getStemmer();
        StringBuffer buffer = new StringBuffer();
        List<String> list = new ArrayList<String>();
        char[] w = new char[501];
        String str = word;
        str = StringUtils.replace(str, ",", " ");
        str = StringUtils.replace(str, "\\n", " ");
        str = StringUtils.replace(str, "`", "");
        str = StringUtils.replace(str, ".", " ");
        str = StringUtils.replace(str, "'", " ");
        str = StringUtils.replace(str, "!", " ");
        str = StringUtils.replace(str, "_", " ");
        str = str.replace("\\([0-9]*\\)", "");
        str = str.replace("\\（[0-9]*\\）", "");
        str = str.replace("[\\u4e00-\\u9fa5]", "");
        str = StringUtils.replace(str, "（", " ");
        str = StringUtils.replace(str, "）", " ");

        try {
            InputStream in = new ByteArrayInputStream(str.getBytes());
            while (true) {
                int ch = in.read();
                if (Character.isLetter((char) ch)) {
                    int j = 0;
                    while (true) {
                        ch = Character.toLowerCase((char) ch);
                        w[j] = (char) ch;
                        if (j < 500) j++;
                        ch = in.read();
                        if (!Character.isLetter((char) ch)) {
                            for (int c = 0; c < j; c++) stemmer.add(w[c]);
                            stemmer.stem();
                            list.add(stemmer.toString());
                            break;
                        }
                    }
                }
                if (ch < 0) break;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return list;
    }

}
